<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<head>
<script>
function boom()
{
  document.getElementById("inxul").appendChild(document.getElementById("floater"));
}
</script>
</head>

<body onload="boom()">

<xul:vbox><span id="inxul"><div/></span></xul:vbox>

<span style="float: left;" id="floater"></span>

</body>
</html>
